Morphology and Biomass Production of Prairie Cordgrasson Marginal Lands

Prairie cordgrass (Spartina pectinata Link.) is indigenous throughout most of the continental United States and Canada to 60°N latitude and is well suited to marginal land too wet for maize (Zea mays L.) and switchgrass (Panicum virgatum L.). Evaluations of prairie cordgrass in Europe and North America indicated it has high potential for biomass production, relative to switchgrass, in short‐season areas. Our objective was to describe morphology and biomass production and partitioning in mature stands of ‘Red River’ prairie cordgrass and determine biomass production of natural populations on marginal land. This study was conducted from 2000 to 2008 in eastern South Dakota. Mean biomass production of mature stands of Red River was 12.7 Mg ha−1. Leaves composed \u3e88% of the biomass, and 60% of the tillers had no internodes. Belowground biomass to a depth of approximately 25 cm, not including roots, was 21 Mg ha−1. Tiller density ranged from 683 tillers m−2 for a 10‐year‐old stand to 1140 tillers m−2 for a 4‐year‐old stand. The proaxis was composed of about eight phytomers, with rhizomes originating at proximal nodes and erect tillers at distal nodes. Vegetative propagation was achieved by both phalanx and guerilla growth. Differences among natural populations for biomass were expressed on gravelly marginal land. However, production, averaged across populations, was low (1.37 Mg ha−1) and comparable to ‘Cave‐In‐Rock’ switchgrass (1.67 Mg ha−1) over a 4‐year period. The large carbon storage capacity of prairie cordgrass in proaxes and rhizomes makes it useful for carbon sequestration purposes. Prairie cordgrass should be compared with switchgrass and other C4 perennial grasses along environmental gradients to determine optimum landscape positions for each and to maximize bioenergy production and minimize inputs

Effects of Ash Application on Cadmium Concentration in Small Mammals

In order to assess the effects of wood ash application to forests on small mammals, we collected bank voles (Clethrionomys glareolus ) and common shrews (Sorex araneus ) from a forest area in southern Finland. Part of the sample population was from sites that had been treated with ash 1.5 years earlier, part from untreated control sites. The ash increased the soil pH and gave an average cadmium load in soil of 44 g ha1.When comparing treated and control areas, we found slightly but significantly lower Cd concentrations in vole muscle, liver, and kidney from treated plots, whereas the Cd concentrations in shrew tissues were greater in animals from treated plots. In voles we detected an increase in Cd concentrations during the 45-d sampling period in treated and untreated plots. The relative weight of kidneys was greater from the ash-treated areas than untreated areas for both voles and shrews. The difference in Cd concentrations between the voles and shrews could be explained by the different food habits

QTL analysis for resistance to foliar damage caused by Thrips tabaci and Frankliniella schultzei (Thysanoptera: Thripidae) feeding in cowpea [Vigna unguiculata (L.) Walp.]

Three quantitative trait loci (QTL) for resistance to Thrips tabaci and Frankliniella schultzei were identified using a cowpea recombinant inbred population of 127 F2:8 lines. An amplified fragment length polymorphism (AFLP) genetic linkage map and foliar feeding damage ratings were used to identify genomic regions contributing toward resistance to thrips damage. Based on Pearson correlation analysis, damage ratings were highly correlated (r ≥ 0.7463) across seven field experiments conducted in 2006, 2007, and 2008. Using the Kruskall–Wallis and Multiple-QTL model mapping packages of MapQTL 4.0 software, three QTL, Thr-1, Thr-2, and Thr-3, were identified on linkage groups 5 and 7 accounting for between 9.1 and 32.1% of the phenotypic variance. AFLP markers ACC-CAT7, ACG-CTC5, and AGG-CAT1 co-located with QTL peaks for Thr-1, Thr-2, and Thr-3, respectively. Results of this study will provide a resource for molecular marker development and the genetic characterization of foliar thrips resistance in cowpea

Flight behaviour of European corn borer infected with Nosema pyrausta

The microsporidian Nosema pyrausta Paillot is a common and widespread pathogen of European corn borer, Ostrinia nubilalis (Hübner), in North America and Europe. Nosema negatively affects European corn borer longevity and fecundity. In this study, we used flight mills to examine the effects of Nosema infection on flight activity of unmated males and females at 1 and 3 days after pupal eclosion, taking the level of infection, as measured by number of Nosema spores per mg of tissue, into consideration. Nosema infection had a significant negative effect on distance, duration and speed of the longest uninterrupted flight, as well as on total distance and duration of flight of 1-day-old males, but not of 3-day-old males or females of either age. However, when insects with a light infection (\u3c15 spores/mg) were pooled with uninfected moths, significant negative effects of a moderate/heavy infection (≥15 spores/mg) were observed for most flight parameters in 1-day-old, but not 3-day-old, moths of both sexes. The magnitude of reduction was often substantial: e.g., distance and duration were sevenfold, and 3.5-fold less, respectively, in 1-day-old females with a moderate/heavy infection. Flight distance and duration were significantly negatively correlated with level of Nosema infection in 1-day-old, but not 3-day-old, moths of both sexes. The percentage of moths of either sex or age with a moderate/heavy Nosema infection flying given distances was less than that of lightly infected (\u3c15 spores/mg) moths. Among uninfected adults, forewing length was positively correlated with several measures of flight performance in males, but not females. However, some performance measures were correlated with wing length in females when infected with Nosema. Nosema infection was associated with reduced adult weight, but not forewing length, suggesting that negative effects of Nosema infection on flight performance are related to reduced energy reserves rather than smaller body size per se

Incomplete functional recovery after delirium in elderly people: a prospective cohort study

BACKGROUND: Delirium often has a poor outcome, but why some people have incomplete recovery is not well understood. Our objective was to identify factors associated with short-term (by discharge) and long-term (by 6 month) incomplete recovery of function following delirium. METHODS: In a prospective cohort study of elderly patients with delirium seen by geriatric medicine services, function was assessed at baseline, at hospital discharge and at six months. RESULTS: Of 77 patients, vital and functional status at 6 months was known for 71, of whom 21 (30%) had died. Incomplete functional recovery, defined as ≥10 point decline in the Barthel Index, compared to pre-morbid status, was present in 27 (54%) of the 50 survivors. Factors associated with death or loss of function at hospital discharge were frailty, absence of agitation (hypoactive delirium), a cardiac cause and poor recognition of delirium by the treating service. Frailty, causes other than medications, and poor recognition of delirium by the treating service were associated with death or poor functional recovery at 6 months. CONCLUSION: Pre-existing frailty, cardiac cause of delirium, and poor early recognition by treating physicians are associated with worse outcomes. Many physicians view the adverse outcomes of delirium as intractable. While in some measure this might be true, more skilled care is a potential remedy within their grasp